balance between weight loss and performance

Hello everyone. First post here. I am returning to the bike after being off for a few years. In the interim, I've managed to gain a few unwanted pounds (about 15 lbs.) I'm looking for a nutrition regimen to follow that will allow me to loose weight while at the same time improving my performance on the bike. Is there a known "general guideline" that I could follow that will allow both weight loss and performance improvment? Perhaps a 'when and what' to eat while training? Thanks.